deleted file mode 100644
--- a/layout/style/CSSVariableImageTable.h
+++ /dev/null
@@ -1,191 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim: set ts=8 sts=2 et sw=2 tw=80: */
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-/* A global table that tracks images referenced by CSS variables. */
-
-#ifndef mozilla_CSSVariableImageTable_h
-#define mozilla_CSSVariableImageTable_h
-
-#include "mozilla/ComputedStyle.h"
-
-#include "nsClassHashtable.h"
-#include "nsCSSPropertyID.h"
-#include "nsCSSValue.h"
-#include "nsTArray.h"
-
-/**
- * CSSVariableImageTable maintains a global mapping
- *   (ComputedStyle, nsCSSPropertyID) -> nsTArray<ImageValue>
- * which allows us to track the relationship between CSS property values
- * involving variables and any images they may reference.
- *
- * When properties like background-image contain a normal url(), the
- * Declaration's data block will hold a reference to the ImageValue.  When a
- * token stream is used, the Declaration only holds on to an
- * nsCSSValueTokenStream object, and the ImageValue would only exist for the
- * duration of nsRuleNode::WalkRuleTree, in the AutoCSSValueArray.  So instead
- * when we re-parse a token stream and get an ImageValue, we record it in the
- * CSSVariableImageTable to keep the ImageValue alive. Such ImageValues are
- * eventually freed the next time the token stream is re-parsed, or when the
- * associated style is destroyed.
- *
- * To add ImageValues to the CSSVariableImageTable, callers should pass a lambda
- * to CSSVariableImageTable::ReplaceAll() that calls
- * CSSVariableImageTable::Add() for each ImageValue that needs to be added to
- * the table. When callers are sure that the ImageValues for a given
- * ComputedStyle won't be needed anymore, they can call
- * CSSVariableImageTable::RemoveAll() to release them.
- */
-
-namespace mozilla {
-namespace CSSVariableImageTable {
-
-namespace detail {
-
-typedef nsTArray<RefPtr<css::ImageValue>> ImageValueArray;
-typedef nsClassHashtable<nsGenericHashKey<nsCSSPropertyID>, ImageValueArray>
-        PerPropertyImageHashtable;
-typedef nsClassHashtable<nsPtrHashKey<ComputedStyle>, PerPropertyImageHashtable>
-        CSSVariableImageHashtable;
-
-inline CSSVariableImageHashtable& GetTable()
-{
-  static CSSVariableImageHashtable imageTable;
-  return imageTable;
-}
-
-#ifdef DEBUG
-inline bool& IsReplacing()
-{
-  static bool isReplacing = false;
-  return isReplacing;
-}
-#endif
-
-} // namespace detail
-
-/**
- * ReplaceAll() allows callers to replace the ImageValues associated with a
- * (ComputedStyle, nsCSSPropertyID) pair. The memory used by the previous list of
- * ImageValues is automatically released.
- *
- * @param aContext The style the ImageValues are associated with.
- * @param aProp    The CSS property the ImageValues are associated with.
- * @param aFunc    A lambda that calls CSSVariableImageTable::Add() to add new
- *                 ImageValues which will replace the old ones.
- */
-template <typename Lambda>
-inline void ReplaceAll(mozilla::ComputedStyle* aStyle,
-                       nsCSSPropertyID aProp,
-                       Lambda aFunc)
-{
-  MOZ_ASSERT(aContext);
-
-  auto& imageTable = detail::GetTable();
-
-  // Clear the existing image array, if any, for this property.
-  {
-    auto* perPropertyImageTable = imageTable.Get(aContext);
-    auto* imageList = perPropertyImageTable ? perPropertyImageTable->Get(aProp)
-                                            : nullptr;
-    if (imageList) {
-      imageList->ClearAndRetainStorage();
-    }
-  }
-
-#ifdef DEBUG
-  MOZ_ASSERT(!detail::IsReplacing());
-  detail::IsReplacing() = true;
-#endif
-
-  aFunc();
-
-#ifdef DEBUG
-  detail::IsReplacing() = false;
-#endif
-
-  // Clean up.
-  auto* perPropertyImageTable = imageTable.Get(aContext);
-  auto* imageList = perPropertyImageTable ? perPropertyImageTable->Get(aProp)
-                                          : nullptr;
-  if (imageList) {
-    if (imageList->IsEmpty()) {
-      // We used to have an image array for this property, but now we don't.
-      // Remove the entry in the per-property image table for this property.
-      // That may then allow us to remove the entire per-property image table.
-      perPropertyImageTable->Remove(aProp);
-      if (perPropertyImageTable->Count() == 0) {
-        imageTable.Remove(aContext);
-      }
-    } else {
-      // We still have a non-empty image array for this property. Compact the
-      // storage it's using if possible.
-      imageList->Compact();
-    }
-  }
-}
-
-/**
- * Adds a new ImageValue @aValue to the CSSVariableImageTable, which will be
- * associated with @aContext and @aProp.
- *
- * It's illegal to call this function outside of a lambda passed to
- * CSSVariableImageTable::ReplaceAll().
- */
-inline void
-Add(mozilla::ComputedStyle* aStyle, nsCSSPropertyID aProp, css::ImageValue* aValue)
-{
-  MOZ_ASSERT(aValue);
-  MOZ_ASSERT(aContext);
-  MOZ_ASSERT(detail::IsReplacing());
-
-  auto& imageTable = detail::GetTable();
-
-  // Ensure there's a per-property image table for this style.
-  auto* perPropertyImageTable = imageTable.Get(aContext);
-  if (!perPropertyImageTable) {
-    perPropertyImageTable = new detail::PerPropertyImageHashtable();
-    imageTable.Put(aContext, perPropertyImageTable);
-  }
-
-  // Ensure there's an image array for this property.
-  auto* imageList = perPropertyImageTable->Get(aProp);
-  if (!imageList) {
-    imageList = new detail::ImageValueArray();
-    perPropertyImageTable->Put(aProp, imageList);
-  }
-
-  // Append the provided ImageValue to the list.
-  imageList->AppendElement(aValue);
-}
-
-/**
- * Removes all ImageValues stored in the CSSVariableImageTable for the provided
- * @aContext.
- */
-inline void
-RemoveAll(mozilla::ComputedStyle* aStyle)
-{
-  // Move all ImageValue references into removedImageList so that we can
-  // release them outside of any hashtable methods.  (If we just call
-  // Remove(aContext) on the table then we can end up calling back
-  // re-entrantly into hashtable methods, as other styles are released.)
-  detail::ImageValueArray removedImages;
-  auto& imageTable = detail::GetTable();
-  auto* perPropertyImageTable = imageTable.Get(aContext);
-  if (perPropertyImageTable) {
-    for (auto it = perPropertyImageTable->Iter(); !it.Done(); it.Next()) {
-      auto* imageList = it.UserData();
-      removedImages.AppendElements(Move(*imageList));
-    }
-  }
-  imageTable.Remove(aContext);
-}
-
-} // namespace CSSVariableImageTable
-} // namespace mozilla
-
-#endif // mozilla_CSSVariableImageTable_h